Time delay control system



Oct. 1, 1940. s. MINNECl TIME DELAY CONTROL SYSTEM Filed Jan. 15, 1938 FI i I .AMU zum Inventor salvatore Minneci,

by is :J/MAM ttorney,

Patented Oct. 1, 1940 UNITED STATES TIME DELAY CONTROL SYSTEM SalvatoreMinneci, Pittsfield, Mass, assignor to General Electric Company, acorporation of New York Application January 15, 1938, Serial No. 185,180

6 Claims.

This invention relates to time delay control systems, and moreparticularly to improvements in time delay control systems for automaticregulators.

' Many regulated quantities contain continual relatively smallfluctuations which it is unnecessary for the regulator to correct andwhich would cause excessive operation of the regulator if it did attempttheir correction. Consequently, time delay means are often included inthe control of automatic regulators, so that they, will only respondwhen the regulated condition or quantity deviates from its normal valuefor a predetermined length of time. a In accordance with this inventiona novel time delay system is employed in which the time delay ispositive and is independent of changes in ambient temperature, circuitvoltage and various other quantities which might efiect the duration ofthe time interval.

An object of the invention is to provide a new and improved time delaycontrol system.

Another object of the invention is to provide a rugged and simplereversible motor-operated adjustable time delay contactor.

The invention will be better understood from the following descriptiontaken in connection with the accompanying drawing and its scope will bepointed out in the appended claims.

Referring now to the single figure of the accompanying drawing, which isa so-called exploded perspective view of a reversible motor-operatedadjustable time delay contactor embodying my invention, there is showntherein a reversible motor I. This motor may be of any suitable type andis shown by way of example as consisting of an element 2 for producingforward rotation of the motor and an element 3 for producing reverserotation of the motor. These elements may correspond to those used inthe small self-starting single phase synchronous motors commonlyemployed to drive electric clocks. motor I is a speed reducing means 4of any suitable type such as speed reducing gearing. Driven by the speedreduction gearing 4 is a crank shaft 5 rigidly fastened to which iscrank 6 carrying a crank pin 1. Loosely mounted on the crank shaft 5 isa gear 8 which is arranged to be driven by the crank 6 by means of adetent 3 carried thereby. The detent is urged into its locking positionby means of a spring I0 and is fastened to a knob II which when pulledtoward the left,

releases the engagement of the gear 3 and he detent 9 and, thus, permitsan adjustment to be made between the angular relation of the crankDriven by the 6 and the gear 8. Carried by'the gear 8is a pin I2.

Arranged for cooperation-with the pin 1 is a lever I3 fastened to ashaft I4 which carries a contact operating member I5 for controlling theopening and closing of a normally open set of contacts I6. Arranged forcooperation with the pin I2 is another lever II which is loosely mountedon the shaft I4 and which is rigidly fastened to a. contact operatingmember I8 for controlling the operation of a normally open set ofcontacts l9 and a normally closed set of contacts 20. A coil spring 2|serves to bias the contacts I6 and 20 to their closed positions and tobias the contacts I9 to their open position.

Carried by the gear 8 is a time scale 22 which is calibrated directly inunits of time delay, so that, for example, the numbers thereon may betaken to represent seconds of time delay. For cooperation with thisscale there is a pointer 23 carried by the crank 6. and the scaledirectly opposite this pointer is viewed through a window 24 in thecrank 6.

The time delay contactor has a normal or reset position and it is inthis position that the parts have been illustrated. This position isalso indicated by the registration of a fixed reference mark 25 and apointer 26 on the crank 8.

The motor elements 2 and 3 are selectively energized from a supplycircuit 21 by means of a suitable circuit control switch 28. When thisswitch is closed in its uppermost position an energizing circuit for theforward motor element 2 is completed through the time delay openingcontacts 20 and when the switch is closed in its lowermost position anenergizing circuit for the reversing motor element 3 is establishedthrough the run back contacts I6.

The operation is such that when the forward direction motor element 2 isenergized, the crank 6 will rotate in a counter-clockwise direction.Substantially the instant that it starts to turn in this direction thepin I will allow the lever I3 and the contact-operating member I5 toturn sufiiciently under the influence of spring 2| to cause closure ofthe contacts l6. After a predetermined amount of counter-clockwiserotation, the pin I2 will engage the lever Il, thus, rotating the memberI8 and causing substantially simultaneous closure of the contacts I9 andopening of the contacts 20. Contacts I9 are the main control contactswhich upon their closure cause the delayed energization of a controlleddevice, such as a regulator motor or operating winding. The contacts 20are normally connected in the energizing circuit of the forward motorelement 2 so that operation of the contactor is immediately stopped whenit reaches its timed out position. This timed out position is of coursecharacterized by the closing of the contacts l9 and the opening of thecontacts 20.

When it is desired to run the contactor back to its normal or resetposition the control switch 28 is moved to its lowermost position. Thiswill energize the reversing motor element through the run back contacts[6 and after a predetermined time the pin I will engage the arm l3,thereby causing opening of the run back contacts [6 and automaticstopping of the contactor.

As indicated by the illustrated relative positions of the crank 6 andthe gear 8, the contactor is set for a time delay of ten seconds. Bypulling out the knob H and rotating the gear clockwise, the time delaymay be increased up to seconds and by rotating it counter-clockwise thetime delay may be reduced to one second. However, it should be realizedthat whether the time delay is in seconds, minutes or any other unit oftime depends merely upon the speed of the motor l and the ratio of thespeed reducing gearing 4,

so that any time delay desired may readily be secured.

While there has been shown and described a particular embodiment of thisinvention, it will be obvious to those skilled in the art that variouschanges and modifications can be made therein without departing from theinvention and, therefore, it is aimed in the appended claims to coverall such changes and modifications as fall within the true spirit andscope of the invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is:

1. An adjustable time delay relay comprising, a normally de-energizedelectric motor having forward and reverse directions of operation, afirst rotatable member having a normal position, means connected to saidmotor for rotating said first member away from its normal position whensaid motor operates in its forward direction, a normally open set ofcontacts for connection in a circuit for energizing said motor forreverse rotation, means operated by said first member for closing saidcontacts when said first member is out of its normal position, a secondrotatable member, adjustable means for connecting said second rotatablemember to be driven by said first rotatable member at any predeterminedangular relation between said members, a set of normally closed contactsfor connection in a circuit for energizing said motor for forwardoperation, means operated by said second rotatable member for openingsaid normally closed set of contacts after said second member has beenrotated a predetermined amount, a set of normally open main controlcontacts, and means operated by said second rotatable member for closingsaid main control contacts after said second rotatable member has beenrotated said predetermined amount.

2. A time delay control system comprising, a reversible electric motor,rotatable contact operating means having a normal position andmechanically connected to be operated by said motor, a set of normallyopen contacts for connection in a reversing circuit for said motor, saidcontacts being closed by said means when it is out of said normalposition, and a set of normally closed contacts for connection in aforward running circuit for said motor, said last-mentioned contactsbeing opened by said means after said motor has rotated a predeterminedamount in its forward direction.

3. An adjustable time delay control system comprising, an electricmotor, speed reduction gearing connected to be driven by said motor, afirst member connected to be rotated by said reduction gearing, a secondmember connected to be rotated by said first member, means for adjustingthe angular relation between said members, and separate contactsconnected respectively to be operated by said members.

4. An adjustable time delay control system comprising, a normallydeenergized electric motor, a first member having a. normal startingposition and connected to be rotated therefrom by said motor, a secondmember connected to be rotated by said first member, time delayedoperating contacts operated by said second member, and means forpermitting adjustment of the angular relation between said members so asto adjust the interval between the time when the first member leaves itsnormal position and the time when the second member operates saidcontacts.

5. An adjustable time delay control system comprising, a normallydenergized electric motor, a first member having a normal startingposition and connected to be rotated therefrom by said motor, a secondmember connected to be rotated by said first member, time delayedoperating contacts operated by said second member, means for permittingadjustment of the angular relation between said members so as to adjustthe interval between the time when the first member leaves its normalposition and the time when the second member operates said contacts, ascale on one of said members calibrated in units of time delay, and apointer on the other of said units for cooperating with said scale.

6. An adjustable time delay control system comprising, a motor havingseparate self-starting single phase synchronous motor elements forcausing motor operation in forward and reverse directions respectively,speed reducing means driven by said motor, a crank having a normalposition from which it is driven by said speed reducing means, a geararranged for concentric rotation with said crank, a detent on said crankfor engaging the teeth of said gear for adjustably fixing the angularrelation between said crank and said gear, a set of normally opencontacts, means operated by said crank whenever it leaves its normalposition for closing said contacts, a second set of normally opencontacts, a set of normally closed contacts, and means operated by saidgear after it has been rotated an amount corresponding to said angularrelation for simultaneously closing said second set of normally opencontacts and opening said set of normally closed contacts.

SALVATORE MINNECI.

